The Linux man-pages project

The Linux man-pages project documents the
Linuxkernel
and C library interfaces that are employed by user-space programs.
With respect to the C library, the primary focus is the
GNU C library
(glibc),
although, where known,
documentation of variations on other C libraries
available for Linux is also included.
The project provides manual pages in the following sections:

1: User commands; man-pages includes a very few Section 1 pages that
document programs supplied by the GNU C library.